U.S. patent number 3,987,000 [Application Number 05/501,559] was granted by the patent office on 1976-10-19 for sprayable polymer composition.
This patent grant is currently assigned to Beiersdorf Aktiengesellschaft. Invention is credited to Gunther Bonitz, Peter Gleichenhagen, Dietrich Schulte.
United States Patent |
3,987,000 |
Gleichenhagen , et
al. |
October 19, 1976 |
Sprayable polymer composition
Abstract
A polymer composition is disclosed which can be sprayed or
otherwise thinly coated on an open wound to serve as a protective
bandage. The composition comprises: A. 10 to 30% by weight of
isobutene relative to total monomer weight; B. 5 to 85% by weight
of total monomer of one or more esters of acrylic or methacrylic
acid and one or more normal or branched, monovalent, primary or
secondary aliphatic alcohols having 1-4 carbon atoms; and C. 5 to
85% by weight of total monomer of one or more maleic acid monoalkyl
esters having 1-12 carbon atoms in the monoalkyl portion of the
molecule.
Inventors: |
Gleichenhagen; Peter (Hamburg,
DT), Schulte; Dietrich (Pinneberg, DT),
Bonitz; Gunther (Hamburg, DT) |
Assignee: |
Beiersdorf Aktiengesellschaft
(DT)
|
Family
ID: |
5891232 |
Appl.
No.: |
05/501,559 |
Filed: |
August 29, 1974 |
Foreign Application Priority Data
|
|
|
|
|
Aug 31, 1973 [DT] |
|
|
2343923 |
|
Current U.S.
Class: |
602/52; 524/320;
524/391; 526/324; 606/214; 523/111; 524/354; 524/559; 526/325;
606/215 |
Current CPC
Class: |
A61L
26/0014 (20130101); A61L 26/0066 (20130101); A61L
26/0076 (20130101); A61L 26/0014 (20130101); C08L
35/02 (20130101); A61L 2300/404 (20130101); A61L
2300/418 (20130101) |
Current International
Class: |
A61L
26/00 (20060101); A61L 015/00 (); C08K 005/01 ();
C08K 005/04 (); C08K 005/10 () |
Field of
Search: |
;260/80.81,31.2R,78.5R,80.8,32.8R,33.4R,33.6UA,33.8UA
;128/155,156,334R ;526/324,325 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lieberman; Allan
Attorney, Agent or Firm: Bierman & Bierman
Claims
What is claimed is:
1. A film forming, sprayable solution for forming a wound bandage
which comprises a copolymer dissolved in a volatile organic
solvent, said copolymer comprising between about 1 and 8 percent by
weight of the solution, said copolymer further comprising:
a. 10-30 percent by weight of total monomers of isobutene,
b. 5-85 percent by weight of total monomers of 1 or more esters of
acrylic or methacrylic acid with straight chain or branched,
monovalent, primary or secondary aliphatic alcohols having 1 to 4
carbon atoms, or their mixtures, and
c. 5 to 85 percent by weight of the total monomers of at least one
maleic acid monoalkyl ester having 1 to 12 carbon atoms in the
alkyl moiety.
2. The solution of claim 1 wherein said volatile organic solvent is
selected from the group consisting of acetic acid ethyl ester,
benzene, methylene chloride, ethanol, acetone and mixtures
thereof.
3. The solution of claim 1 further comprising a liquefied
propellant gas miscible with the organic solvent and wherein the
copolymer comprises between about 1 to 8 percent by weight of the
solution containing the liquefied propellant gas.
4. The solution of claim 3 in which the liquefied propellant gas is
a halogen hydrocarbon or a mixture of different halogen
hydrocarbons.
5. The solution of claim 1 in which the copolymer is present in a
concentration of 4 to 6 percent by weight, based on the weight of
the solution.
6. The solution of claim 1 in which the monomer units with carboxyl
groups in the copolymer comprise up to 50 percent by weight of said
acrylic and/or methacrylic acid ester units.
7. The solution of claim 1 in which the free carboxylic groups in
the copolymer are at least partially reacted with an amino
alcohol.
8. The solution of claim 1 which further comprises a blood
coagulating antiseptic substance, a deodorant, or both.
Description
This application claims the priority of German application 23 43
923 filed Aug. 31, 1973.
The present invention concerns a film-forming polymer composition,
especially such as can be sprayed from aerosol containers. It is
sprayed on or otherwise applied in thin layers to a cut, abrasion,
or surgical wound that is to be bandaged. After the solvent
evaporates, a thin, coherent film forms, which covers the site of
injury.
In addition to using textile bandaging materials and adhesive
bandages (plasters) to cover wounds, the uses of which are
generally connected with a series of disadvantages, it is known
that thin, transparent, colorless films with sufficient water vapor
permeability can be used. They are formed locally by applying or
spraying a polymer solution of appropriate composition onto the
wounded area, and by evaporating the solvent. They are capable of
adapting themselves to all skin movements at the injured site
because of their elasticity and flexibility.
Such polymer solutions, which form a film over the injured site
that closes the wound area against the outside, can have quite
varying compositions. They are also called "liquid bandaging
materials" or "liquid plasters". Such solutions are preferably
packaged in aerosol containers together with a propellant and find
commercial use in this way. When required, they can be sprayed onto
the wound by activating a valve button.
These film-forming, sprayable solutions are usually formed in
volatile, non-toxic organic solvents such as ethyl acetate,
methylene chloride, chloroform, acetone, ethanol, or their
mixtures, with or without the addition of surgical spirits. To
produce these solutions various polymers of acrylic and methacrylic
acid esters, such as polymethyl methacrylate, polyethyl
methacrylate, poly-2-ethoxy ethyl methacrylate, or their mixtures
have hitherto been used (DT-AS1 008 874, DT-AS 1 253 414, US-PS 2
949 443). Since these polymers, when used to produce a wound
bandage, frequently yielded brittle films which tore easily, it was
necessary to remove this undesired effect by amalgamating
softeners. For this purpose, synthetic softeners, such as sebacates
and phthalates, were suggested, in addition to esters of fatty
acids. Besides using polymethacrylates and polyacrylates or their
copolymers, plasticized cellulose - aceto-butyrate is also known
for this purpose (GB-PS 836 520). Further polymers and polymer
mixtures which have been suggested as essential components of
film-forming, sprayable solutions to produce wound bandages are
vinyl acetate/vinyl chloride mixtures and ethyl cellulose with
various additives (DT-AS 1 077 382), polyvinylpyrrolidone (US-PS 3
073 794), as well as copolymers of acrylates and methacrylates,
with selected monomers such as n-tert. butylacrylamide (US-PS 3 413
254), or .beta.-dimethylaminoethyl-methacrylate or tert.
butylamino-ethyl-methacrylate. Here the latter mixed polymers can
be made hydrophilic or even water soluble, by partial salt
formation (US-PS 3 305 510, US-PS 3 305 513, US-PS 3 341 505).
Other wound bandage sprays have been described which yield films
that can be removed by washing with soap and water. They contain as
essential components, mixtures of polyvinyl acetals with copolymers
or vinylpyrrolidone and vinylacetate (DT-OS 1 642 063), or
plasticized copolymers of vinylacetate and crotonic acid (Fr-PS 2
144 587).
Finally, it is known in connection with compositions that can be
sprayed from aerosol containers that the film can be generated on
the wound in such fashion that a two-chamber aerosol container is
used. Separate portions of softening agent in a volatile organic
solvent, and powdered polymers are sprayed on the wounded area
either sequentially or simultaneously, from the separate container
chambers. After the two substances are mixed and the solvent
evaporated, the film is then formed. Here, the polymer should
consist of a high proportion of hydroxyalkyl acrylate or
methacrylate contained in the mixed polymer, and the softening
agent should consist of a polyol, a polyalkylene glycol, or a
derivative thereof (US-PS 3 577 516).
A large number of characteristics are required of a film-forming
polymer which can be sprayed in solution form, in an easily
volatile, non-toxic, organic solvent, and which is to produce a
high quality wound bandage. These characteristics can in part be
combined only with difficulty, since some of them normally exclude
one another.
Thus, the polymer must form a thin, tough, flexible, elastic film
on the skin, which adapts very well to all skin movements (even at
the joints) without tearing. It must therefore be quite soft, but
on the other hand, may not block, since otherwise undesired
stickiness easily results in skin creases, especially at
temperatures above 35.degree. C. Furthermore, dirt particles may
not adhere to the film. Despite its soft, rubberlike character, the
film should be resistant to peeling, lest the sprayed bandage be
worn off by clothing. Even on rough sections of skin, films
generated by spraying must be smooth and impervious. Furthermore,
the film should be transparent and colorless so as to be
inconspicuous and to afford observation of the wound and of its
healing. Also, it must have no unpleasant odor.
In addition to the named mechanical requirements, the polymer must
be sufficiently soluble in various solvents which are customarily
used for the present purpose. These include ethyl acetate,
methylene chloride and/or ethanol or their mixtures with the
addition of liquified propellants, such as chlorofluorinated
hydrocarbons. The viscosities of these solutions, even at higher
solid material content, (up to about 8 weight percent), should be
as low as possible in order that the solution be easily sprayable.
This means that the required mechanical properties must be obtained
with polymers of a relatively low degree of polymerization.
Furthermore, the film produced by the solution must be
semipermeable and hydrophilic, in order that moisture given off by
the skin, as well as volatile components of the wound secretions
can penetrate the film in vapor form, and thus adequate skin
breathing is assured. At the same time, the formed film must be
insoluble in body fluids and must adhere to the skin under their
influence. On the other hand, the hydrophilic character of the
polymer must be such that the film formed therefrom can outlast
rather short wetting periods during normal washing and bathing
without suffering degradation of any kind. Its adherence to acid or
alkaline skin surfaces must be so great that the sprayed bandage
remains intact without noticeable flaking even on heavily
perspiring skin parts, for about three days, under not too great
mechanical stress. The film should not discolor on skin, even for
longer periods of time, under the influence of light and air. It
must resist chemical attack by skin secretions, especially
perspiration. Furthermore, it must be toxicologically
unobjectionable and not irritate skin. When stored in solution for
a longer period of time, the polymer must not decompose, nor may
discolorations or milkiness appear. Even after aging for a
protracted period, the film-forming substance must remain odor
free.
All of these requirements in one polymer are difficult to achieve
and were heretofore unachieved until the present invention was
made.
Thus, for example, those polymers which contain
.beta.-dimethylamino-ethylmethacrylate units or side chains
carrying similar amino groups, tend to discolor strongly during
production, and especially after aging. Such polymers produce
brittle, easily torn films and must be plasticized for the
anticipated purpose by adding softening agents. Thus, a danger
exists that these softening agents may be partially absorbed by the
skin in addition to having a possible irritating effect. This is
not an inconsiderable factor from a toxicological point of view.
The same is true for the addition of resins which soften and which
lend adhesion to such polymers. Occasionally, they too produce
allergic reactions on the skin. Using polyvinyl pyrrolidone
preparations as wound bandage spray results in films that are much
too water soluble. These become sticky under the influence of
greater air humidity, such as normally occurs in the areas near the
skin. Using poly-2-ethoxy ethyl methacrylate results in products
which, after aging, produce an unpleasantly smelling, unclear film.
Finally, it should also be mentioned that many of the film-forming
polymers or polymer mixtures which have been suggested for use as
wound bandage sprays, and which have been described in the patent
literature, are not clearly soluble in the usual solvent -
propellant mixtures. Hence, when sprayed from an aerosol container,
they show an unfavorable, practically unsuitable spray pattern. On
the other hand, two-chamber aerosols are too expensive and
cumbersome in manufacture as well as in use and yield films which
dry too slowly.
The present invention, therefore, is based on the task of creating
a polymer for a wound bandage spray, that satisfies the many
requirements stated above to the maximum extent possible, and which
has none of the cited disadvantages of known polymers or polymer
mixtures, and which is excellently suitable for producing a wound
bandage in the form of a film-forming, sprayable, stable solution.
In particular, the film-forming substance should meet the necessary
requirements without addition of auxiliary agents, such as
softening agents.
It has been found that this advantageous combination of
characteristics can surprisingly be obtained when a mixed
polymeride is used for the film-forming, sprayable solution to
produce the polymeride for a wound bandage, which is easily
manufactured by radical polymerization of relatively simply
constructed and economical monomers, namely by mixed polymerization
of isobutene with lower acrylic or methacrylic acid esters and
maleic acid monoesters.
The subject of the invention is thus a film-forming, sprayable
polymeride solution to produce a wound bandage comprising a
solution of a copolymer dissolved in a volatile organic solvent.
The copolymer comprises:
a. 10 to 30 weight percent isobutene (relative to the total monomer
weight);
b. 5 to 85 weight percent of the total monomer weight of one or
more esters of acrylic or methacrylic acid with one or more
straight-chain or branched monovalent, primary or secondary
aliphatic alcohols having one to four carbon atoms;
c. 5 to 85 weight percent of the total monomer weight of one or
more maleic acid monoalkyl esters with 1 to 12 carbon atoms in the
alkyl moiety.
The maleic acid monoalkyl ester can be replaced wholly or in part
by an .alpha., .beta. unsaturated monocarboxylic acid, such as
acrylic or methacrylic acid, or by basic monomer units containing
amino groups, or their mixtures. Alternatively, up to about 75
weight percent of the maleic acid monoester fraction can be
replaced by fumaric acid dialkyl ester with one to six carbon atoms
in the alkyl residue.
Preferable esters of acrylic or methacrylic acid with
straight-chain or branched monovalent, primary or secondary
aliphatic alcohols with one to four carbon atoms, or their
mixtures, which can be used as component (b) are acrylic acid
methyl ester, acrylic acid ethyl ester, acrylic acid n-butyl ester,
as well as methacrylic acid methyl ester. The latter is
particularly useful when mixed with an acrylic acid ester.
Among the series of maleic acid monoalkyl esters (component c)
maleic acid-mono-isopropyl ester, maleic acid-mono-n-butyl ester,
maleic acid mono-2-ethylhexyl ester, and maleic acid-mono-n-dodecyl
ester, as well as their mixtures, have proven particularly suitable
to produce the polymers according to the invention.
Acrylic acid and methacrylic acid are particularly useful as
.alpha., .beta. unsaturated monocarboxylic acids, which can replace
wholly or in part the maleic acid monoalkyl ester in producing the
film-forming polymers according to the invention. The alkaline
monomer units containing amino groups preferably comprise
methacrylic acid-2-dimethyl-amino ethyl ester (.beta.-dimethyl
amino-ethylmethacrylate).
Fumaric acid-di-isopropyl ester, fumaric acid-diethyl ester, and
fumaric acid-di-n-butyl ester can be used as fumaric acid dialkyl
esters with one to six carbon atoms in the alkyl residue, which can
be used up to about 75 weight percent of the maleic acid ester
fraction in making the copolymer.
The monomer units with carboxyl or amino groups in the copolymer
preferably comprise up to 50 weight percent of the acrylic and/or
methacrylic acid ester units.
The exact ratio of the quantity of acrylic or methacrylic acid
ester component (component b) and of the maleic acid monoalkyl
ester component (component c) or of their monomers, which can
replace the maleic acid monoester(s) wholly or in part, can be
varied within the limits given supra. The choice of kind and
quantity of monomers which are to be copolymerized must be
determined in such a way that polymers are obtained which are
completely polymerized under normal conditions, and such that they
can be easily sprayed in solution with an organic solvent,
particularly by means of an added propellant, and that they yield a
thin, flexible, elastic, transparent and colorless film on the skin
with the advantageous characteristics described above. This choice,
however, can easily be determined by a skilled chemist by routine
experimentation.
Preparation of the copolymer of this invention is suitably
performed in an autoclave with an anchor stirrer. The
polymerization temperature is chosen in the range usual for free
radical polymerization, preferably between 60.degree. C and
80.degree. C. Known substances for this kind of polymerization such
as e.g. azoisobutyric acid dinitrile (AIBN) or benzoyl peroxide.
The isobutene is added to excess and simultaneously serves as
solvent. The non-converted fraction of isobutene can be removed by
venting it after the polymerization reaction is complete. Good
results are obtained when about two mol isobutene is added to the
monomer mixture, for 1 mol of the sum of acrylic or methacrylic
acid esters (component b) and maleic acid monoester (component c).
The mol ratio of monomer units in the formed mixed polymeride in
this case comes to about two mol acrylic or methacrylic acid ester
units, and malic acid monoester units per one mol isobutene units.
This corresponds to a fraction of about 20 to 25 weight percent
isobutene units, in addition to 75 to 80 weight percent of the sum
of acrylic or methacrylic acid ester units and maleic acid
monoester units.
In order to keep the reaction substance in stirrable condition
while the polymerization reaction is going on, it is recommended,
for some formulas, that a small amount of acetic acid ethyl ester
or methylene chloride be added after about 3 hours reaction time to
the reaction mixture, as an additional solvent in the autoclave
(reaction pressure: 6-8 atm at 60.degree.-65.degree. C reaction
temperature). After a reaction time of about 5 hours, a small
amount of initiator can still be added to accelerate the
polymerization. The reaction is complete after about 12 hours.
Then, the excess isobutene is evaporated and recovered for
subsequent reactions.
The relative viscosities of 1% solutions of copolymers obtained in
this way, in toluol at 25.degree. C, have measured values between
1.300 and 1.570 and are relatively low. The values are dependent of
the composition of the monomer mixture as well as the chosen
reaction conditions. The resulting mixed polymers are readily
soluble in toluene, benzene, methylene chloride, acetone, acetic
acid ethyl ester, and/or ethanol, and their mixtures with the
benzene. Surprisingly, the addition of regulators such as
tetrabromethane, mercaptans, or the like, to the monomer mixture,
to obtain relatively low levels of polymerization is not required,
in contrast to the situation prevailing in the production of known
copolymers for the same purpose. These additives are not required
to perform the described polymerization in autoclaves and are also
undesirable from toxicological points of view. Isobutene as such
already has sufficient control effect for the anticipated
purpose.
Copolymers are known which are produced by free radical
polymerization of isobutene with acrylates or methacrylates.
According to the type and amount of the acrylic or methacrylic acid
ester used, products with different characteristics are obtained.
These can be wax-like, adhesive or non-adhesive, and tough-elastic.
For example, the copolymer of methyl acrylate and isobutene (with
an isobutene content of 25 weight percent) is quite soft and has a
rubber-like elasticity which is favorable for the anticipated
purpose. But it has the disadvantage of blocking behavior, which is
exhibited when a film produced from such a polymer is used on the
skin. This results in dirt particles being held fast, and in the
film surface strongly sticking together in creases of the skin.
It could not be foreseen, and therefore was surprising, that adding
a fraction of lower maleic acid monoalkyl esters to the monomer
mixture prior to polymerization (preferably up to 50 weight
percent, for lower ones up to 20 weight percent) results in a
polymer which yields a thin, colorless, soft, and flexible film on
the skin. In addition to favorable rubber-like elastic
characteristics, this film no longer blocks. Even when moisture is
present, it adheres excellently to the skin without creating a
feeling of tension. Because of its semipermeable, hydrophilic
character, it makes possible ready diffusion of water vapor as well
as adequate skin respiration. Such films, according to the
invention, resist short stresses when washing with soap and water
without a tendency to flake, and without other reductions in
quality. They are colorless and odorless and remain so even after
being carried for protracted periods on the skin. In addition, they
resist peeling quite well. The free carboxyl groups in the
polymeride effect a weakly acidic character in the spray wound
bandage, which has a beneficial effect on antiseptic
properties.
By neutralizing a part or all of the free carboxyl groups in the
mixed polymeride with amino alcohols, such as e.g.
2-methyl-2-amino-propandiol-1,3 or amines carrying similar hydroxyl
groups, the hydrophilic character can be increased even more,
should this be desirable for special applications. No
discolorations occur in this way.
The solution of the polymer in an easily volatile, nontoxic,
organic solvent, to produce the sprayable polymer solution is done
in familiar fashion and offers no difficulties. The concentration
of the copolymer in the solution should be about 1 to 8 weight
percent, preferably 4 to 6 weight percent. Here, the term "solvent"
includes the volatile, organic solvent referred to supra to
dissolve the polymer as well as a liquid propellant, which is
preferably added to the solution and which is miscible with actual
solvent.
The relatively highly concentrated polymer solution, which is
obtained by dissolving the copolymer can be charged into an aerosol
container, together with a propellant in the form of liquified
propellant gas, such as a halogen hydrocarbon, and other solvents.
It is preferably used commercially in this form. Some special mixed
polymers are also easily soluble in ethanol-halogen hydrocarbon
propellant mixtures. The ethanol content of such mixtures can be
suppressed to about 5 weight percent without precipitation of the
polymer occuring. In addition to nitrogen, carbon dioxide or
dinitrogen monoxide, the following find good use as propellant
gases: trichloromonofluoromethane, dichlorodifluoromethane,
dichlorotetrafluoroethane, and especially their mixtures. For the
practical application of producing a wound bandage, such polymer
solutions are preferably used which have a content of film-forming
copolymers between 4 and 8 weight percent relative to the total
mixture, including propellants. Lower contents of film-forming
mixed polymers generally yield films that are too thin. At higher
concentrations, the spray pattern is unfavorably influenced during
the spraying process. In addition to the preferred film formation
by spraying the polymer solution from an aerosol container, it can
also be applied to the skin by a spray container with a compressed
rubber ball, or by painting on. For this type of application to the
skin, there are many possibilities. The wound bandage spray
according to the invention, especially serves to cover small
surface wounds and can furthermore be used for larger, already
healing wounds, in place of the traditional wound bandage. The
solution can additionally contain blood coagulating, antiseptic, or
bacteriostatic substances and/or aromatic materials (odorants) that
are non-irritating to the skin.
The following examples are provided to more clearly point out the
present invention. They are in no way meant as limiting the
invention, however.
EXAMPLE 1
A mixture of 464.9 g acrylic acid methyl ester (5.4 mol), 30.0 g
methacrylic acid methyl ester (0.3 mol) and 47.5 g maleic acid
monoisopropyl ester, to which 3.0 g azoisobutyric acid dinitrile
(AIBN) was added, were placed in a stirring autoclave of 2 liter
capacity. The autoclave was equipped with an anchor stirrer and
with mantle heating. The apparatus was first carefully flushed with
nitrogen in order to remove remaining oxygen. Afterwards, 673 g
isobutene (12 mol) were pumped into the autoclave and the reaction
mixture was heated to 60.degree. C.
After polymerization was initiated, the temperature in the
autoclave rose to 63.degree. C. The pressure in the autoclave was
5-6 atm at the beginning of polymerization, and during the reaction
it rose to about 8-9 atm. After a reaction time of 41/2 hours, a
solution of 2.0 g AIBN in 50 g ethyl acetate was forced into the
autoclave. After another 2 hours, the same amount of initiator
solution was again added. After a total of 12 hours, polymerization
was complete. Excess isobutene was vented at about 60.degree. C,
and was recovered for further formulations. The reaction product
was treated with ethyl acetate and the resulting solution was
removed from the autoclave through a valve at its bottom. The
relative viscosity of the resulting copolymer in 1% toluene
solution at 25.degree. C was 1.349. CH analysis on the polymer
produced in the described manner showed a content of about 21 to 25
weight percent of isobutene units.
Various aerosol compositions, intended for filling aerosol
containers, were produced with the resulting copolymer. In addition
to ethyl acetate, methylene chloride was also used as solvent. When
the mixture contained solid materials between 4 and 8 percent, a
good spray pattern was obtained, corresponding to the intended use.
The aerosol compositions with various liquified chlorofluoridated
hydrocarbons and their mixtures, to which usual additives such as
antiseptics can be added, are stable against aging. The films
resulting by spraying this material on the skin and by evaporation
of the solvent, caused no kind of skin irritation, had the above
described desirable good mechanical properties, adhered well,
showed no change of any kind after brief washing with warm soap
solution and remained colorless and odorless after being carried
for some time on the skin. Even when usual additives, such as
antiseptics, were added to the mixtures, the properties of the film
produced therefrom were not changed negatively. If the film is
desired to be more hydrophilic, neutralization with an amino
alcohol proves useful.
EXAMPLE 2
A formula with the following ingredients were polymerized in the
manner described in example 1:
______________________________________ acrylic acid methyl ester
464.9 g (5.4 mol) maleic acid-mono-n-butyl ester 103.3 g (0.6 mol)
isobutene 673.0 g (12 mol) azoisobutyric acid dinitrile (AIBN) 7.0
g ethyl acetate (solvent for AIBN) 100.0 g
______________________________________
The resulting copolymer contained 23 to 25 weight percent isobutene
(relative viscosity: 1.324). After partial neutralization of the
free carboxyl groups of the polymer with
2-amino-2-methyl-propandiol-1,3 (at least 50% of the free carboxyl
groups of the mixed polymeride should be neutralized), the polymer
was fully soluble even in ethanol-halogen hydrocarbon mixtures, and
could be sprayed well from aerosol containers.
The mechanical properties, adhesion and age resistance of the film
produced from this mixed polymeride were nearly identical to those
described according to Example 1.
EXAMPLE 3
A monomer mixture of the following composition was polymerized as
described in Example 1:
______________________________________ acrylic acid methyl ester
490.7 g (5.7 mol) maleic acid-mono-isopropyl ester 47.5 g (0.3 mol)
isobutene 673.0 g (12 mol) AIBN 7.0 g ethyl acetate 100.0 g
______________________________________
The resulting copolymer contained 23 to 25 weight percent
isobutene. The relative viscosity of a 1% solution of the polymer
in toluene at 25.degree. C was 1.451.
Properties of the film produced from this polymer were quite
similar to those described in example 1.
EXAMPLE 4
A monomer mixture of the following compositions was polymerized as
described in Example 1:
______________________________________ acrylic acid methyl ester
413.2 g (4.8 mol) methacrylic acid methyl ester 114.1 g (1.14 mol)
acrylic acid 5.5 g (0.06 mol) isobutene 673.0 g (12 mol) AIBN 7.2 g
______________________________________
Deviating from example 1, in this formulation 50 g of the monomer
mixture of acrylic acid methyl ester, methacrylic acid methyl ester
and acrylic acid were retained, and 4.8 g of the cited amount of
AIBN were dissolved in it. After polymerization was started by
addition of 2.4 g of the initiator, 27.4 g of the above described
initiator solution was added to the reaction mixture after each
41/2 hours of reaction time. In this way, the addition of a further
solvent could be avoided. The reaction mixture became a viscous
liquid towards the end of the reaction and partial precipitation
occurred. The reaction product did, however, remain capable of
being stirred. The pressure rose from 6 to 9 atm during the
reaction. After the excess isobutene was vented and recovered, the
polymer could be dissolved in a solvent to facilitate its being
carried off. The solvents include ethyl acetate, methylene chloride
or their mixtures. Ethyl acetate/ethanol mixtures were equally
useful.
The relative viscosity of a 1% solution of the copolymer in toluene
at 25.degree. C was 1.570.
The polymer formed films with properties that were similar to those
cited in example 1, but somewhat harder. They could be made softer
by adding to the mixture skin-care agents, primarily lanolin
alcohols, and thus could be adapted for the requirements of a high
quality wound bandage.
EXAMPLE 5
A monomer mixture of the following composition was polymerized as
described in example 1:
______________________________________ acrylic acid methyl ester
348.7 g (4.05 mol) methacrylic acid methyl ester 165.2 g (1.65 mol)
methacrylic acid-2-dimethyl- aminoethyl ester 47.2 g (0.3 mol)
isobutene 673.0 g (12 mol) AIBN 7.2 g ethyl acetate 100.0 g
______________________________________
The relative viscosity of a a1% solution of the copolymer obtained
according to this example was about 1.539 in toluene at 25.degree.
C.
The polymer formed a weakly alkaline film on the skin. It adhered
well and had good mechanical properties. The alkaline character of
the copolymer could be removed by adding an acid such as a small
amount of benzoic acid. Thus the adhesion of the film was not
appreciably reduced.
A composition that could be sprayed from aerosol containers was
produced according to the following recipe:
5.0 g copolymer
10.0 g methylene chloride (dichloromethane)
35.0 g ethyl acetate
0.05 g antiseptic (2,4,4'-trichloro-2'-hydroxy-diphenyl-ether)
50.0 g mixture of trichloro monofluoro methane and dichloro
difluoro methane (Freon 11/12) in the ratio 50:50
0.008 g odorant (tonalid)
To produce the wound bandage spray, the polymer was dissolved with
stirring in the solvent mixture of methylene chloride and ethyl
acetate. The antiseptic and deodorant were then added to the
solution, and stirring was continued until everything was
dissolved. After filtering, the solution was charged into an
aerosol container, which was then equipped with a valve head, and
was sealed gas tight. A propellant gas comprising
trichloromonofluoromethane and dichlorodifluoromethane was then
filled into the aerosol container under pressure, through the valve
in the valve head (pressure fill procedure).
EXAMPLE 6
A monomer mixture of the following composition was polymerized in
the manner described in example 1:
______________________________________ acrylic acid ethyl ester
420.5 g (4.2 mol) maleic acid-mono-isopropyl ester 284.7 g (1.8
mol) isobutene 673.0 g (12 mol) AIBN 7.0 g ethyl acetate 100.0 g
______________________________________
The reaction was started with 3 g azoisobutyric acid dinitrile
(AIBN). After 4 and 6 hours reaction time, aliquots of 2 g AIBN
dissolved in 50 g acetic acid ethyl ester, were added to the
reaction mixture. Total reaction time was 20 hours.
The relative viscosity of a 1% solution of the copolymer obtained
in this way was 1.290, in ethyl acetate at 25.degree. C.
The polymer was readily soluble in ethyl acetate, acetone,
methylene chloride, and after partial neutralization with
2-amino-2-methyl-propandiol-1,3, was also soluble in ethanol and
mixtures of ethanol and liquified chlorofluoridated
hydrocarbons.
EXAMPLE 7
A monomer mixture of the following composition was polymerized as
described in Example 6:
______________________________________ acrylic acid-n-butyl ester
499.9 g (3.9 mol) maleic acid-mono-isopropyl ester 332.1 g (2.1
mol) isobutene 673.0 g (12 mol) AIBN 7.0 g ethyl acetate 100.0 g
______________________________________
The relative viscosity of a 1% solution of the resulting copolymer
was 1.258 in ethyl acetate at 25.degree. C.
The polymer had similar solubility properties as that produced
according to example 6. It was insoluble in toluene and
benzene.
EXAMPLE 8
A monomer mixture of the following composition was polymerized in
accordance with example 6:
______________________________________ acrylic acid methyl ester
279.8 g (3.25 mol) methacrylic acid methyl ester 150.2 g (1.5 mol)
maleic acid-mono-n-dodecyl ester 71.1 g (0.25 mol) isobutene 561.0
g (10 mol) AIBN 7.0 g ethyl acetate 100.0 g
______________________________________
The relative viscosity of a 1% solution of the resulting polymer
was 1.360 in toluene at 25.degree. C.
The polymer was soluble in ethyl acetate, methylene chloride,
toluene and their mixtures with benzene, and the usual liquified
propellants, but was insoluble in ethanol.
EXAMPLE 9
A monomer mixture of the following composition was polymerized in
the manner described in example 1:
______________________________________ acrylic acid methyl ester
241.1 g (2.8 mol) acrylic acid ethyl ester 40.0 g (0.4 mol) maleic
acid-mono-2-ethyl-hexyl ester 182.6 g (0.8 mol) isobutene 449.0 g
(8 mol) AIBN 3.6 g ethyl acetate 50.0 g
______________________________________
The reaction was started with 1.8 g of initiator. After a reaction
time of 6 hours, a solution of 1.8 g azoisobutyric acid dinitrile
(AIBN) in 50 g acetic acid ethyl ester was forced into the
autoclave. The pressure in the autoclave rose from 6.8 atm to 8.3
atm during the reaction. Total reaction time was 20 hours.
The resulting copolymer was soluble in ethyl acetate, acetone and
ethanol. For filling aerosol containers, it could be processed with
a mixture having an ethanol fraction of only 5%, the remaining 95%
consisting of liquified propellant (mixture of chlorofluoridated
hydrocarbons). A composition which was sprayable from aerosol
containers could also be produced according to the following recipe
in the manner described in example 5:
10.0 g copolymers
90.0 g ethanol
100.0 g mixture of trichloro monofluoro methane and dichloro
difluoro methane (Freon 11/12) in the ratio of 40:60.
EXAMPLE 10
A monomer mixture of the following composition was polymerized as
described in example 1:
______________________________________ acrylic acid methyl ester
275.5 g (3.2 mol) maleic acid-mono-2-ethyl hexyl ester 182.6 g (0.8
mol) isobutene 449.0 g (8 mol) AIBN 5.4 g ethyl acetate 100.0 g
______________________________________
The reaction was started with 1.8 g AIBN. After reaction times of 4
and 6 hours, aliquots of 1.8 g of initiator in 50 g ethyl acetate
was each time charged into the autoclave. The initial autoclave
pressure of 7.0 atm, rose to 8.5 atm during the reaction. Total
reaction time was 20 hours.
The copolymer so obtained was soluble in ethyl acetate, acetone and
ethanol. For filling into aerosol containers, it could be processed
with an ethanol fraction of only 5% with the remaining 95%
consisting of liquified propellant (mixture of chlorofluoridated
hydrocarbons). A further composition which could be sprayed from
aerosol containers is produced according to the following recipe in
the manner described in example 5:
5.0 g copolymer
45.0 g ethanol
0.05 g antiseptic
50.0 g mixture of trichloro monofluoro methane and dichloro
difluoro methane (Freon 11/12) in the ratio 50:50
0.0008 odorant
EXAMPLE 11
A monomer mixture of the following composition was polymerized as
described in example 1:
______________________________________ acrylic acid methyl ester
300.0 g (3.5 mol) maleic acid-mono-2-ethyl hexyl ester 150.0 g (0.7
mol) fumaric acid-di-isopropyl ester 150.0 g (0.75 mol) isobutene
561.0 g (10 mol) AIBN 5.0 g ethyl acetate 50.0 g
______________________________________
The reaction was started with 3.0 g AIBN. After a reaction time of
5 hours, a solution of 2.0 g of the initiator in 50 g ethyl acetate
was charged into the autoclave. The initial autoclave pressure of 5
atm rose to 7 atm during the reaction. Total reaction time was 20
hours.
The copolymer so obtained was readily soluble in ethanol. The
relative viscosity of a 1% solution of the resulting copolymer was
1.271 in toluene at 25.degree. C.
By simply testing the ratio of solvent or solvent mixture and the
propellant composition, good spray behavior, well adapted to the
intended purpose can be obtained in all cases. Since the
viscosities of the polymer solution are quite low, no undesirable
thread formation occurs during spraying. The aerosol mixtures are
completely clear, storage proof solutions. The advantage of the
films obtained on the skin by one or more sprayings with
intermediate drying periods, lies in their very short drying time,
even if ethanol and ethyl acetate are used. The films do not block,
nor do they show a tendency to stick in skin creases and are
resistant to soap alkali. Even short, warm showers or tub baths do
not attack the film. Nevertheless, perspiration and wound secretion
vapors can penetrate the film without dissolving it. The film does
not attract dirt and adheres for several days as a dense, flexible
and elastic layer of skin. Eventually it begins to flake off with
increasing repulsion of epithelial cells. It does this quickly and
without leaving debris. The films remain colorless and odor free
even when carried for long periods of time. Besides their use to
cover cuts, abrasions and healing surgical wounds, they can also be
used to cover salve applications to protect clothing, as well as to
cover other kinds of medical preparations applied to the skin.
* * * * *